Field of the Invention
The embodiments described herein generally relate to the field of sensors that measure a material's dielectric constant, conductivity, and temperature, which may be used to determine soil moisture and salinity or other properties of materials such as grain moisture content, cement curing, etc.
Description of the Related Art
As of 2011, the global gardening and outdoor living industry was already worth a staggering $187 billion. In North America alone, sales of plants, seeds, and other garden paraphernalia reached nearly $58 billion. These statistics are compelling evidence of humanity's affinity toward verdant foliage and vibrant blossoms. Indeed, many millions of Americans, whether or not they consider themselves gardening enthusiasts, are engaged in some form of lawn care and gardening activities. There are tens of millions of acres of residential lawns in the United States. Even households that do not have access to residential lawns are keen to install planters, and to find alternative, smaller scale ways to cultivate plants both indoors and outdoors.
But maintaining a garden has also become an increasingly difficult and unattainable endeavor in recent years. First, global climate changes have made it harder to create and sustain the various conditions required for different plants to survive. While weather conditions (e.g., temperature, sunlight, and rainfall) often fluctuate outside of historical norms and sometimes to extremes, plants typically need very steady and specific levels of moisture, heat, and light exposure. Consequently, even seasoned horticulturists are struggling to create and maintain ideal plant habitats. In addition, gardening is also now a much more costly pursuit. Many regions around the world experience severe and chronic drought conditions, and water has become a more precious commodity than ever before. The rates for water in the United States, for instance, have increased drastically in recent years (e.g., 75% between 2000 and 2012) as have the fines and penalties for over and misusage of water. Meanwhile, the water shortages that plague many parts of the country are not expected to abate any time soon.
Temperamental weather and soaring water costs are just a few of the challenges that overwhelm conventional gardening methods. Under- and overwatering, for example, are a persistent and pricey problem because most households program sprinkler systems according to a static schedule or frequency, causing plants to be watered regardless of current moisture levels in the soil or imminent rainfall. In addition, gardens tend to be individually unique ecosystems, although the differences are often incredibly nuanced and hardly perceptible to the average person. Very often, a plant that flourishes in one location will mysteriously flounder in another. Alice, for example, can fail to grow peonies in her garden even though the same type of plant thrives in her neighbor Bob's yard. This is because conventional approaches to gardening disregard particularized and real-time data with respect to each individual garden ecosystem. Plant care guidelines, which are typically found on placards that accompany commercially available plants, provide only very general recommendations (e.g., light exposure, type of fertilizer, and watering and feeding frequency). But based on these types of instructions alone, it is still nearly impossible to systematically recreate an ideal growing environment. So more often than not, for the average person, successfully growing a plant often entails an interminable and frustrating succession of trial and error.